Concomitant familial hypocalciuric hypercalcemia and single parathyroid adenoma: a case report

Background Primary hyperparathyroidism (PHPT) is a common endocrine disorder and the most frequent benign cause of hypercalcemia. PHPT is characterized by autonomous hypersecretion of parathyroid hormone (PTH), regardless of serum calcium levels. Familial hypocalciuric hypercalcemia (FHH) is a rare, benign syndrome only affecting the regulation of calcium metabolism. FHH is an autosomal-dominant genetic disease with high penetrance, caused by an inactivating variant in the CASR gene encoding the calcium-sensing receptor (CaSR). We present a unique case of concomitant PHPT and FHH without clinically actionable variants in MEN1. Case presentation A 47-year-old Caucasian man with severe hypercalcemia, genetic FHH, and initially normal parathyroid scintigraphy was referred for endocrine evaluation due to nonspecific symptoms. Biochemical evaluation showed elevated serum ionized calcium and PTH. The calcium–creatinine clearance ratio was low. All other biochemical measures were normal, including kidney function. Genetic evaluation was redone and confirmed FHH. A new parathyroid scintigraphy showed a significant single adenoma corresponding to the lower left gland. The patient underwent parathyroidectomy, and a parathyroid adenoma was removed. A reduced level of hypercalcemia persisted due to FHH. Conclusions The correct diagnosis of the underlying cause of hypercalcemia is important to ensure the right treatment. Patients with FHH should avoid operative treatment, and PHPT should be differentiated from MEN1 to determine whether surgery should include parathyroidectomy with removal of one adenoma or 3.5 hyperplastic parathyroid glands.

The Utility of 18F-Fluorocholine PET/CT in The Imaging of Parathyroid Adenomas

Aim: to estimate sensitivity of 18F-FCH PET/CT in preoperative localisation of hyperfunctioning parathyroid glands in patients with primary hyperparathyroidism (PHPT). Methods: 65 consecutive patients with PHPT who underwent neck ultrasound (US) and 99mTc/99mTc-MIBI dual-phase parathyroid scintigraphy were prospectively enrolled. Twenty-two patients had unsuccessful parathyroid surgery prior to the study. PET/CT scans were performed 65.0 ± 13.3 min after injection of 218.5 ± 31.9 MBq of 18F-fluorocholine (FCH). Three experienced nuclear medicine physicians assessed the detection rate of hyperfunctioning parathyroid tissue. Response to parathyroidectomy and clinical follow-up served as a reference test. Per-patient sensitivity and positive predictive value (PPV) were calculated for patients who underwent surgery.Results: 18F-FCH PET/CT was positive in 61 patients, and negative in four. US and parathyroid scintigraphy showed positive and negative results in 20 , 45 and 17, 48, respectively. US showed nodular goiter in 31 patients and chronic thyroiditis in 9 patients. Parathyroid surgery was performed in 43 (66%) patients. 18F-FCH PET/CT yielded sensitivity of 100% (95% CI [87.99-100]) and PPV of 85.7% (95% CI [70.77-94.06]). Similar values were observed in patients with chronic thyroiditis, nodular goiter, and patients after an unsuccessful parathyroid surgery. PET/CT identified hyperparathyroidism complications (kidney stones, osteoporotic bone fractures and brown tumours) in 11 patients.Conclusions: 18F-FCH PET/CT effectively detected hyperfunctioning parathyroid tissue and its complications. The method showed excellent sensitivity and positive predictive value, including patients with nodular goiter, chronic thyroiditis and prior unsuccessful parathyroidectomy. PET/CT performance was superior to neck ultrasound and parathyroid scintigraphy.

Evaluation of the Radiological Findings of the Patints Having Surgical Intervention For The Primary Hyperparathyroidism

Objective: In this study, we aimed to compare the results of ultrasonography and Tc-99m sestamibi dual phase parathyroid scintigraphy with postoperative pathology findings in patients with primary hyperparathyroidism. Methods: The study was carried out with 96 patients, who had surgical intervention for primary hyperparathyroidism and followed up in the Endocrinology and Metabolism Clinic, between January 2010-December 2015. Demographic data and preoperative laboratory results of the patients were reviewed. Diagnostic accuracy and compliance were calculated by comparing imaging methods with surgical localization and histopathological evaluation results. Results: Parathyroid adenomas were detected in 75, parathyroid hyperplasia in 12, and parathyroid carcinoma in 5 and suspect pathology results in 4 patients. The mean preoperative calcium (11.25 mg/dl) and parathormone (400.06 pg/ml) levels were determined. Ultrasonography had an estimated diagnostic sensitivity of 58.7% and a specificity of 38.5% in cases with parathyroid adenoma. It was observed that ultrasonography has not any diagnostic significance, and it is not in accordance with histopathological diagnosis (Kappa=-0.018, p=0.851). Diagnostic sensitivity, and specificity of scintigraphy were found to be 58.7%, and 38.5%, respectively. It was observed to be only fairly concordant, and significant according to histopathological diagnosis (Kappa=0.221, p=0.047). Conclusion: Tc-99m MIBI dual-phase parathyroid scintigraphy, a highly sensitive and noninvasive imaging technique, is clearly superior to the ultrasonography in detecting parathyroid adenomas and locating regions correctly.

Synchronous symptomatic parathyroid carcinoma and parathyroid adenoma with incidental follicular thyroid carcinoma

We describe the case of an 89-year old Caucasian woman admitted with confusion and severe clinical manifestations of acute hypercalcaemia. There was no history suggestive of any malignancy and initial management included correction of the hypercalcaemia with intravenous fluid therapy. Sestamibi parathyroid scintigraphy and neck ultrasonography demonstrated a 4cm left-sided thyroid lesion and a nearly 2cm right-sided thyroid lesion. The patient underwent a total thyroidectomy and parathyroidectomy. Histology confirmed a concomitant parathyroid adenoma, parathyroid carcinoma and follicular thyroid carcinoma. To our knowledge, this is the first reported case in the literature.

Added Value of Subtraction SPECT/CT in Dual-Isotope Parathyroid Scintigraphy

Background: Adding subtraction single-photon emission computed tomography/computed tomography (SPECT/CT) to dual isotope (I-123 and Tc-99m-sestamibi) subtraction parathyroid scintigraphy is not widely implemented. We aimed to assess the added value of dual isotope subtraction SPECT/CT over single isotope SPECT/CT as an adjunct to dual isotope planar pinhole subtraction scintigraphy. Methods: Parathyroid scintigraphies from 106 patients with an estimated total of 415 parathyroid glands who (1) were diagnosed with primary hyperparathyroidism, (2) underwent dual isotope subtraction scintigraphy in the Department of Nuclear Medicine, Gentofte Hospital, Denmark throughout 2017 and (3) underwent subsequent parathyroidectomy, were included. The original dual isotope planar pinhole subtraction plus dual isotope subtraction SPECT/CT (dual/dual method) exams were retrospectively re-evaluated using only Tc-99m-sestamibi SPECT/CT (dual/single method). Statistics were calculated per parathyroid. Surgical results confirmed by pathology served as reference standard. Results: The dual/dual method had higher sensitivity than the dual/single method (82% (95%CI 74%–88%) vs. 69% (95%CI 60%–77%)) while specificity, positive and negative predictive values (PPV and NPV) were similar (specificity 96% vs. 93%, PPV’s 87% vs. 82% and NPV’s 89% vs. 93%). Reader confidence was higher when employing the dual/dual method (p = 0.001). Conclusions: The dual/dual method can be considered superior to the dual/single method in the preoperative imaging in primary hyperparathyroidism.